Gas discrimination by simultaneous sound velocity and attenuation measurements using uncoated capacitive micromachined ultrasonic transducers

Chemically functionalized or coated sensors are by far the most employed solution in gas sensing. However, their poor long term stability represents a concern in applications dealing with hazardous gases. Uncoated sensors are durable but their selectivity is poor or non-existent. In this study, multi-parametric discrimination is used as an alternative to selectivity for uncoated capacitive micromachined ultrasonic transducers (CMUTs). This paper shows how measuring simultaneously the attenuation coefficient and the time of flight under different nitrogen mixtures allows to identify hydrogen, carbon dioxide and methane from each other and determine their concentration along with identification of temperature and humidity drifts. Theoretical comparison and specific signal processing to deal with the issue of multiple reflections are also presented. Some potential applications are monitoring of refueling stations, vehicles and nuclear waste storage facilities.

Consolidated nuclear waste storage in Andrews, Texas: An integrated technical and policy risk analysis

Over the last 50 years, nuclear energy has reduced US energy-related CO2 emissions by over 30 gigatons compared to if the same electricity were produced by fossil fuels such as coal and natural gas. However, many kilotons of spent nuclear fuel have accumulated at different sites across the country, and sociopolitical factors have frustrated efforts to address the challenge of nuclear waste disposal. Presently, a consolidated interim storage facility in Andrews, Texas, provides a promising temporary solution. In this paper, we compare the technical and policy risks of the project to continued storage at independent spent fuel storage installations. Our results indicate that the cost of the radiological risk is low (<$30,000) for both scenarios. However, policy and societal considerations will impact the viability of the proposed consolidated interim storage facility. The safety and suitability of this interim storage facility will be affected by when a permanent repository becomes available, whether insurance for offsite waste storage is available, and the impact of climate risks. Although a consolidated interim storage facility at Andrews can potentially serve as a safe and economically advantageous solution, we highlight why these concerns must be addressed for the successful implementation of this facility, and more broadly for the future of the US nuclear industry.

Ultrasonic Echo Localization Using Seismic Migration Techniques in Engineered Barriers for Nuclear Waste Storage

In the framework of non-destructive-testing advanced seismic imaging techniques have been applied to ultrasonic echo data in order to examine the integrity of an engineered test-barrier designed to be used for sealing an underground nuclear waste disposal site. Synthetic data as well as real multi-receiver ultrasonic data acquired at the test site were processed and imaged using Kirchhoff prestack depth migration reverse time migration (RTM). In general, both methods provide a good image quality as demonstrated by various case studies, however deeper parts within the test barrier containing inclined reflectors were reconstructed more accurately by RTM. In particular, the image quality of a specific target reflector at a depth of 8 m in the test-barrier has been significantly improved compared to previous investigations using synthetic aperture focusing technique, which justifies the considerable computing time of this method.

The Secret of the Copper Box: public experiments and the prospects of living archives of Swedish nuclear waste

This paper approaches the question of nuclear safety in relation to the prospects of living archives, and in particular, it explores two public events where sociocultural aspects of nuclear waste management in Sweden were enacted. Drawing on an ongoing research collaboration with the Swedish Nuclear Fuel and Waste Management Company (SKB), the paper examines (1) a grass-roots play entitled Kopparkistans hemlighet (or The Secret of the Copper Box), and (2) a drawing competition hosted by schools located near a nuclear waste storage facility in the Östhammar municipality, considering how these events help reproduce certain kinds of social and cultural responsibility. Contributing to critical debates in the social sciences and humanities intersecting questions of memory preservation, nuclear waste, and post-nuclear natures, we consider how the forms of responsibility produced through these public experiments inform important, albeit unconventional, modes of nuclear waste management insofar as they suggest how long-lived nuclear waste sites might become living archives without assuming a narrow notion of heritage and human memory preservation for all time and space. To conclude, we evaluate how the legacy of the two events might be incorporated into wider strategies of nuclear waste management.

What is good drinking water? 41 years of water conflicts around the Nuclear Research Centre Karlsruhe, 1956–1997

Drinking water in Germany is usually praised as the best-controlled food that can be enjoyed almost without exception. What constitutes high-quality drinking water is defined by law and drinking water should “inspire enjoyment, in other words, it should be colourless, clear, cool and odourless as well as tasty” (Deutsches Institut für Normung, 2017, DIN 2000:2017-02). Since this food is one of the basic human needs, it receives special social attention. When in 1956, the idyllic Rhine valley in the borderlands between the south west of Germany and France was turned into the nuclear capital of Germany with the siting of the Nuclear Research Centre in Leopoldshafen north of Karlsruhe, the local community feared especially a reduction of the water quality. This early perception of water risks ran like a thread through the history of the Nuclear Research Centre and the local population. This paper traces back the long-lasting conflict between the people in the Hardtwald area, where Karlsruhe and Eggenstein-Leopoldshafen are located, who valued their rural surroundings and lived mostly from agriculture in the 1950s and the claims as well as hopes of the Federal Republic of Germany, which saw the federal reactor station as central for the country's future flourishment in the post-war period (Gleitsmann, 2011). This clash of values between the Nuclear Research Centre, the different governments and the people of the Hardtwald area continued up until the 1990s, when the municipality of Eggenstein-Leopoldshafen made plans to take over one of the water wells of the Nuclear Research Centre. The takeover became a strategic component in the municipality's Water Concept 2000, through which it aimed at modernising and securing its drinking water supply for the future. During the hearing, opponents cited past violations of rules and free interpretations of threshold values as the basis for their counter arguments. This body of knowledge from the past was knowledge lived by the opponents of the Water Concept 2000. The background information from 41 years shaped their risk perception. Historicizing risk is valuable in the way of gaining a deeper understanding of local resistance against nuclear sites. Risk perception is not a linear process and relies heavily on communication processes as well as the recognition of different value systems. Social science research on resistance against nuclear siting often remains in the moment, even though historians have shown that there is a deeper history behind the opposition. Additionally, historical research often lacks both a theorisation and a conceptualisation of the issues portrayed. Seen from a wider perspective, sociologically informed historical research can contribute to future decision-making concerning nuclear sites, such as nuclear waste storage as well as other technological sites perceived as being risky. Being able to understand where increased risk perceptions come from, how increased resistance occurred and also which mistakes could have been avoided, paves the way for understanding cooperation and for finding sustainable solutions.

Hans Jonas, Günther Anders, and the Atomic Priesthood: An Exploration into Ethics, Religion and Technology in the Nuclear Age

This article investigates the ethical implications of the notion of an Atomic Priesthood, an artificially constructed religion built around the preservation of knowledge related to nuclear-waste storage by using the work of Hans Jonas (1903–1993) and Günther Anders (1902–1992). Building on Jonas’ The Imperative of Responsibility from 1979 and Anders’ The Outdatedness of Human Beings from 1956, this article participates in the debate regarding the ethics of the post-closure marking of nuclear-waste storage sites. Assuming that we have a moral obligation toward future generations, as Jonas argued, even after the nuclear-waste storages have been filled and closed, there remains a need to communicate the danger of these sites to future civilizations to whom our languages and other semiotic systems are incomprehensible. Discussing the hypothetical concept of the Atomic Priesthood, an artificial religion whose central purpose would be to make it taboo to approach certain “impure” sites where our civilization had buried nuclear waste, this article argues that due to the unsolved ethical stakes, technological solutions are unequipped to deal with the long-term ramifications of nuclear power.

Gas Discrimination by Simultaneous Sound Velocity and Attenuation Measurements using Uncoated Capacitive Micromachined Ultrasonic Transducers

Chemically functionalized or coated sensors are by far the most employed solution in gas sensing. However, their poor long term stability represents a concern in applications dealing with hazardous gases. Uncoated sensors are durable but their selectivity is poor or non-existent. In this study, multi-parametric discrimination is used as an alternative to selectivity for uncoated capacitive micromachined ultrasonic transducers (CMUTs). This paper shows how measuring simultaneously the attenuation coefficient and the time of flight under different nitrogen mixtures allows to identify hydrogen, carbon dioxide and methane from each other and determine their concentration along with identification of temperature drift. Theoretical comparison and specific signal processing to deal with the issue of multiple reflections are also presented. Some potential applications are monitoring of refueling stations, vehicles and nuclear waste storage facilities.

The Use of Controlled Dissolution Glasses to Consolidate and Create Permeable or Impermeable Minerals in Formation

Scope Controlled dissolution glasses form a permanent consolidating mineral matrix inside formations with either permeable or impermeable properties. The unique solution has a low injection viscosity and can be easily injected into a wide range of formations. The application method is simple and does not require multiple fluids or pre- and post-flushing. This paper focuses on the benefits of controlled dissolution glasses and potential applications in the oil and gas industry. Methods, Procedures, Process Controlled dissolution glasses have been researched extensively by Glass Technology Services (GTS) since 1999 for the biomedical industry, nuclear waste storage industry, and defense and aerospace industries. GTS together with operators have been performing research and development for the oil industry over the last 10 years. The research investigated different glass compositions to determine their injectability and change in formation properties post-treatment. Sandstone, chalk, and shale formations were used in the testing. Flow testing using a Hoek cell and a core flood apparatus was used to determine the post-treatment permeability. For post-treatment strength measurement, Brazilian tensile strength tests and modified cone penetration tests were used to determine tensile strength and shear strength respectively. The testing evaluated different mixing fluids, such as water and different brines, compatibility, corrosion testing, and concentrations. Results, Observations, Conclusions The testing identified different glass compositions and concentrations that are suitable for different applications and formations. Certain glass compositions increase tensile strength significantly while also maintaining the permeability in the formation. Other glass compositions have similar tensile strength increase, but result in an impermeable seal. The liquid glass solutions react with the formation to form a mineral precipitation inside the formation. The reaction with the formation occurs quickly at downhole conditions, within hours of placement. The glass can be mixed with water and variety of brines to form a stable solution across a range of densities. The testing and results to date have laid the foundation for use in a variety of consolidation and P&A applications in oil and gas wells. Testing is ongoing for a chalk and sandstone consolidation solution and for a sealing solution. Novel/Additive Information These novel glass solutions can solve many of the production and instability challenges that plague weak formations. The glasses can be injected into very low permeability formation to either seal or consolidate.